Myocardial fibrosis is increasingly associated with arrhythmia, contractile dysfunction, and ventricular remodeling, significantly increasing the risk of sudden cardiac death. Hypertension and diabetes trigger fibrotic processes in the heart, placing a high percentage of the American populace at risk, yet the study of fibrosis and early identification of fibrotic development in high-risk patients is hindered by inadequate fibrosis imaging methods.
Magnetic resonance imaging (MRI) of the heart has emerged as a powerful method by which to identify the presence of dense fibrotic tissue following intravenous (IV) infusion of the contrast agent gadolinium with a delayed contrast enhanced (DCE)-MRI approach. However, myocardial fibrosis can be spatially variable at low densities (termed diffuse fibrosis), or spatially focalized at high densities (termed dense fibrosis), often transitioning from diffuse to dense states as part of disease progression. The sensitivity of DCE-MRI limits detection to dense fibrosis, at which point the 2-year event free survival rate of patients is approximately 50%. Additionally, DCE-MRI techniques face significant limitations in that a large portion of the target patient population is excluded from receiving the required administration of gadolinium-DTPA, and that scan times are lengthy.
The ability to identify the emergence of fibrosis during earlier diseases stages would open a large window for potential therapeutic intervention, as well as create a platform by which to study fibrosis non-invasively and to design targeted therapies. Accordingly, there exists a need to develop an improved MRI methods and systems for myocardial fibrosis and other diseases.